US20170315230A1 - Detecting Rain Intensity With Traffic Radar - Google Patents
Detecting Rain Intensity With Traffic Radar Download PDFInfo
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- US20170315230A1 US20170315230A1 US15/499,414 US201715499414A US2017315230A1 US 20170315230 A1 US20170315230 A1 US 20170315230A1 US 201715499414 A US201715499414 A US 201715499414A US 2017315230 A1 US2017315230 A1 US 2017315230A1
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- 238000005259 measurement Methods 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 20
- 238000004891 communication Methods 0.000 claims 4
- 238000001514 detection method Methods 0.000 description 14
- 238000001556 precipitation Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 230000003292 diminished effect Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001010 compromised effect Effects 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000011022 operating instruction Methods 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/91—Radar or analogous systems specially adapted for specific applications for traffic control
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/95—Radar or analogous systems specially adapted for specific applications for meteorological use
- G01S13/951—Radar or analogous systems specially adapted for specific applications for meteorological use ground based
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/40—Means for monitoring or calibrating
- G01S7/4004—Means for monitoring or calibrating of parts of a radar system
- G01S7/4021—Means for monitoring or calibrating of parts of a radar system of receivers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
- G01S7/411—Identification of targets based on measurements of radar reflectivity
- G01S7/412—Identification of targets based on measurements of radar reflectivity based on a comparison between measured values and known or stored values
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/07—Controlling traffic signals
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Definitions
- the present invention relates to the field of signalized traffic control systems having radar cameras to sense when a vehicle approaches a predetermined area and then instructs the traffic controller accordingly.
- Signalized traffic control systems are used in many locations to aid in traffic management at intersections and otherwise. Such systems have cameras for traffic detection. These cameras typically use radar of microwave frequencies for operation. However, there are numerous conditions where detection is not possible with radar cameras. In view of this, means have been devised to detect these conditions via video and give a call to the traffic light controller for detection during these adverse periods. One such event is heavy rain.
- radar using microwave frequencies have the characteristic that range is reduced as rain intensity increases. Normally this is only for very heavy rain, i.e. rainfall greater than two (2) inches/hour or more, but can be a serious problem when rain is much greater than 2 inches/hour or when no reduction in range is allowed.
- the present invention is a traffic control system, device, and method that detects rain intensity with traffic radar, especially, but not necessarily, in or with respect to a signalized traffic control system.
- the traffic control system uses its own traffic radar camera and programmed computing device to detect rain intensity, then adjust or modify traffic light operation accordingly.
- detected rain intensity is compared to a rain intensity threshold. If the detected rain intensity is a particular level relative to the rain intensity threshold, the system will operate the signalized traffic control system in a rain intensity detected mode.
- the rain intensity detected mode has the system hold a call to a traffic light controller during the time when rain intensity is determined to be a value relative to the rain intensity threshold (e.g. above the rain intensity threshold).
- the traffic control system includes a radar camera, traffic controller, and a programmed computing device (e.g. computer) with memory, the programming (program instructions) in accordance with the principles of the present invention.
- the computing device with memory and program instructions may or may not be incorporated into the traffic controller.
- the method includes one or more of the steps of sampling radar from the camera, measuring characteristics of raindrops (e.g. the number of raindrops, the size of the raindrops, and raindrop reflection) within a predetermined range or area (a raindrop intensity range or area) from the radar camera, calculating rain intensity using the measured, detected or determined characteristics of the raindrops, determining an equivalent radar cross section, determining rain intensity, comparing the determined rain intensity with a rain intensity threshold, and, holding notification (“call”) to the traffic controller while the rain intensity is above the threshold.
- the traffic control system may also hold the call for an additional period of time (e.g. 5 seconds) after the rain intensity has diminished below the threshold.
- the method may include determining an average rain intensity using rain intensity over a given number of rain intensity calculations. This may include calculating a rain intensity factor using the average number of raindrops and an equivalent radar cross section.
- FIG. 1 is an exemplary diagram of a signalized traffic control system of the present invention
- FIG. 2 is a graph of rain intensity vs. attenuation vs. frequency
- FIG. 3 is a diagram of U.S. rainfall intensity in inch/hour for a 2 year, 1 hour storm event
- FIG. 4 is a flow chart of a manner of operation of the present signalized traffic control system with rain intensity determination using the radar camera of the signalized traffic control system in accordance with the principles of the present invention.
- FIG. 5 is a flow chart of another manner of operation of the present signalized traffic control system with rain intensity determination using the radar camera of the signalized traffic control system in accordance with the principles of the present invention.
- FIG. 1 shows an exemplary traffic control system 1 using a traffic light or signal 72 (a “signalized traffic control system”).
- the traffic control system 1 shows an intersection or crossing of two streets with a single traffic light or signal 72 , it being understood that the present invention is applicable to other types of intersections, T's, roundabouts, and/or the like having one or more traffic lights/signals.
- the traffic control system 1 includes a radar camera 80 connected to a traffic controller 16 contained within an enclosure 18 via a connection 10 .
- the radar camera 80 may be wirelessly connected to the traffic controller 16 if desired.
- the traffic controller 16 is connected via wire 82 to a computer/computing device 20 having memory for storing program instructions, programming, operating instructions and the like, as well as other typical electronic components of a computer/computing device.
- the traffic controller 16 may be wirelessly connected to the computer/computing device 20 if desired.
- the traffic controller 16 is also connected to the traffic light/signal 72 via wire or wirelessly.
- the radar camera 80 and/or the computer/computing device 20 are/is configured to monitor a field of view 6 that includes a portion of the road and a stop bar area.
- the field of view 6 may be adjusted as desired to cover a particular distance/area size.
- the radar camera 80 and/or the computer/computing device 20 further provides a rain intensity detection/measurement area/field of view 9 for detecting rain intensity 81 .
- the size of the area and distance covered by the detection/measurement area/field of view 9 may be chosen as desired.
- a vehicle 4 is shown coming into the stop bar area being monitored by the radar camera 80 field of view 6 .
- the radar detects the vehicle 4 and sends a message to the traffic controller 16 .
- the traffic controller activates the green light on the traffic light/signal 72 .
- the rain intensity detection/measurement area 9 is adjustable in distance from the radar camera 80 .
- a typical value of measurement is ten feet (10′). Parameters or characteristics are derived from this radar measurement and used by the present invention, parameters/characteristics such as, but not limited to, raindrop count, raindrop size, size of raindrop reflection, and radar cross section of each raindrop.
- the radar signal is attenuated and it becomes critical to ascertain when the intensity is at a level which will disrupt the detection of vehicles as they pull into the stop bar/detection area 6 or any other area where detection is desired. If the rain intensity detection is too sensitive the intersection loses efficiency. If the rain intensity detection is not quick enough then you risk vehicles being left stranded.
- Rainfall intensity may be classified as described in Met Office (August 2007), “Fact Sheet No. 3: Water in the Atmosphere” and such may be used in the present invention. Other systems may be used. From the system, rain intensity may be classified as:
- Violent rain when the precipitation rate is >50 mm (2.0 in) per hour.
- Microwave (radar) attenuation in dB can be characterized by rain intensity over frequency as shown in the graph of FIG. 2 .
- This or similar information is preferably, but not necessarily, used in determining rain intensity per the present invention.
- the graph shows that violent rain/tropical downpour rainfall rates of greater than 2 inches/hour can cause significant attenuation at the frequency of interest, 24 GHz. Thus, the effectiveness of radar cameras is diminished.
- the map of FIG. 3 shows that there are many areas in the United States where violent rain/tropical downpour situations occur. Thus, during these times, the operation of the traffic control system may be compromised.
- a radar range calculation is:
- Radar Output Power is from the radar head product spec.
- the table below summarizes radar degradation in worst case scenarios.
- the range utilized in the table below is based on the vehicle being a car.
- the range without rain attenuation is 600 feet:
- stop bar detection should remain functional through heavy rain conditions. There are situations where there is a need to be able to detect throughout the entire 600 feet range. In these situations, the radar detects the rain intensity and places a call to the traffic controller during the period that rain intensity is above the threshold.
- a signalized traffic control system may thus include rain intensity detection/determination per the principles of the present invention, in its traffic signal (light) operation.
- One method is presented in the flowchart 100 of FIG. 4 .
- the signalized traffic control system turns on with a Start 102 .
- the Intersector (system) programming powers on, initializes, calibrates, error checks, sets a rain threshold, and initializes rain intensity programming 106 .
- the rain intensity is then compared to a rain intensity threshold (threshold) 110 . If the rain intensity is greater than the threshold (True), then a rain intensity counter (counter) of a given interval (e.g. 5 minutes) is set 111 . The calls on all outputs of the cabinet (traffic controller) are then placed and held. Thereafter the system continues 114 which waits for a rain event (or the continuation of the rain event) and takes rain measurements 106 . If the rain intensity is not greater than the threshold (False) the system determines if the rain intensity counter is zero (0) 116 . If the rain intensity counter is not equal to zero (False), the rain intensity counter is decreased 117 .
- a rain intensity threshold threshold 110 . If the rain intensity is greater than the threshold (True), then a rain intensity counter (counter) of a given interval (e.g. 5 minutes) is set 111 . The calls on all outputs of the cabinet (traffic controller) are then placed and held. Thereafter the system continues 114 which wait
- the system continues 114 , then waits for a rain event (or the continuation of the rain event) and takes rain measurements 106 . If the counter is zero (True), normal operation of the traffic controller ensues, and calls are placed to the traffic controller as each car enters or is in the zone 118 . Thereafter, the system continues 114 , then waits for a rain event and takes measurements 106 .
- the signalized traffic control system turns on with a Start 202 .
- the Intersector (system) programming powers on, initializes, calibrates, error checks, sets a rain threshold, and initializes rain intensity programming 206 .
- Average rain intensity is then calculated using the currently calculated rain intensity and a given number of previously calculated rain intensity values (e.g. 19 previously calculated rain intensity values) 210 .
- the average rain intensity is then compared to a rain intensity threshold (threshold) 212 . If the rain intensity is greater than the threshold (True), then a rain intensity counter (counter) of a given interval (e.g. 5 minutes) is set 213 , and calls on all outputs on the cabinet (traffic controller) are placed and held. Thereafter the system continues 214 which waits for a rain event (or the continuation of the rain event) and takes rain measurements 206 . If the rain intensity is not greater than the threshold (False) the system determines if the rain intensity counter is greater than zero (0) 216 . If the counter is not greater than zero (False), normal operation of the traffic control system ensues 218 .
- a rain intensity threshold threshold
- the system continues 114 , then waits for a rain event (or the continuation of the rain event) and takes rain measurements 106 . If the counter is greater than zero (True), the rain timer and decremented 217 . Thereafter, the system continues 114 , then waits for a rain event (or the continuation of the rain event) and takes rain measurements 106 .
- the radar samples approximately twenty (20) times a second. From each sample a list of objects and radar properties may be created. In order to detect rain intensity, the radar is able to count the number of rain drops in the radar field of view in a short distance. The default range used is three (3) meters, or approximately ten (10) feet. In this range, the radar normally detects from 0 to 25 drops of rain depending on intensity.
- Radar also has a property where the reflected signal strength can be corrected to show equivalent Radar Cross Section (RCS).
- RCS Radar Cross Section
- ARD Average Rain Drops
- ARD Average of Radar Cross Section
- Rain Intensity Average (Rain Drops) ⁇ (150-Average (Radar Cross Section in dB)).
- This new variable, Rain Intensity Factor increases when either the number of rain drops increases or the size of the rain drops increases, which are directly correlated to increased rain intensity. From this, a customizable threshold can be set to specify the minimum rain intensity level to place a constant call to the traffic controller.
- the reaction to increasing rain is instantaneous, as soon as the Rain Intensity value crosses the Threshold value a “RAIN” alert is activated.
- the radar In addition to holding the call while RAIN is above the threshold, the radar will hold the call for additional 5 minutes after the rain has dropped below the threshold to ensure everything is operating normally again. This time is programmable and could be set to any value.
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- Engineering & Computer Science (AREA)
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Abstract
Description
- This U.S. non-provisional patent application claims the benefit of and/or priority under 35 U.S.C. §119(e) to U.S. provisional patent application Ser. No. 62/328,329 filed Apr. 27, 2016 titled “Detecting Rain Intensity With Traffic Radar,” the entire contents of which is specifically incorporated herein by reference.
- The present invention relates to the field of signalized traffic control systems having radar cameras to sense when a vehicle approaches a predetermined area and then instructs the traffic controller accordingly.
- Signalized traffic control systems are used in many locations to aid in traffic management at intersections and otherwise. Such systems have cameras for traffic detection. These cameras typically use radar of microwave frequencies for operation. However, there are numerous conditions where detection is not possible with radar cameras. In view of this, means have been devised to detect these conditions via video and give a call to the traffic light controller for detection during these adverse periods. One such event is heavy rain.
- Unfortunately, radar using microwave frequencies have the characteristic that range is reduced as rain intensity increases. Normally this is only for very heavy rain, i.e. rainfall greater than two (2) inches/hour or more, but can be a serious problem when rain is much greater than 2 inches/hour or when no reduction in range is allowed.
- It is therefore an object of the present invention to provide a system, device and/or method for detecting rain intensity with traffic radar. It is also an object of the present invention to provide a signalized traffic control system having a radar camera that can detect rain intensity. It is further an object of the present invention to provide a signalized traffic control system having a radar camera that can detect rain intensity and adjust traffic signal operation accordingly.
- The present invention is a traffic control system, device, and method that detects rain intensity with traffic radar, especially, but not necessarily, in or with respect to a signalized traffic control system.
- The traffic control system uses its own traffic radar camera and programmed computing device to detect rain intensity, then adjust or modify traffic light operation accordingly. In one form, detected rain intensity is compared to a rain intensity threshold. If the detected rain intensity is a particular level relative to the rain intensity threshold, the system will operate the signalized traffic control system in a rain intensity detected mode. In one form, the rain intensity detected mode has the system hold a call to a traffic light controller during the time when rain intensity is determined to be a value relative to the rain intensity threshold (e.g. above the rain intensity threshold).
- The traffic control system includes a radar camera, traffic controller, and a programmed computing device (e.g. computer) with memory, the programming (program instructions) in accordance with the principles of the present invention. The computing device with memory and program instructions may or may not be incorporated into the traffic controller.
- The method includes one or more of the steps of sampling radar from the camera, measuring characteristics of raindrops (e.g. the number of raindrops, the size of the raindrops, and raindrop reflection) within a predetermined range or area (a raindrop intensity range or area) from the radar camera, calculating rain intensity using the measured, detected or determined characteristics of the raindrops, determining an equivalent radar cross section, determining rain intensity, comparing the determined rain intensity with a rain intensity threshold, and, holding notification (“call”) to the traffic controller while the rain intensity is above the threshold. The traffic control system may also hold the call for an additional period of time (e.g. 5 seconds) after the rain intensity has diminished below the threshold.
- The method may include determining an average rain intensity using rain intensity over a given number of rain intensity calculations. This may include calculating a rain intensity factor using the average number of raindrops and an equivalent radar cross section.
- Further aspects of the present invention will become apparent from consideration of the drawings and the following description a form of the invention. A person skilled in the art will realize that other forms of the invention are possible and that the details of the invention can be modified in a number of respects without departing from the inventive concept. The following drawings and description are to be regarded as illustrative in nature and not restrictive.
- The features of the invention will be better understood by reference to the accompanying drawings which illustrate a form of the present invention, wherein:
-
FIG. 1 is an exemplary diagram of a signalized traffic control system of the present invention; -
FIG. 2 is a graph of rain intensity vs. attenuation vs. frequency; -
FIG. 3 is a diagram of U.S. rainfall intensity in inch/hour for a 2 year, 1 hour storm event; -
FIG. 4 is a flow chart of a manner of operation of the present signalized traffic control system with rain intensity determination using the radar camera of the signalized traffic control system in accordance with the principles of the present invention; and -
FIG. 5 is a flow chart of another manner of operation of the present signalized traffic control system with rain intensity determination using the radar camera of the signalized traffic control system in accordance with the principles of the present invention. -
FIG. 1 shows an exemplarytraffic control system 1 using a traffic light or signal 72 (a “signalized traffic control system”). Thetraffic control system 1 shows an intersection or crossing of two streets with a single traffic light orsignal 72, it being understood that the present invention is applicable to other types of intersections, T's, roundabouts, and/or the like having one or more traffic lights/signals. - The
traffic control system 1 includes aradar camera 80 connected to atraffic controller 16 contained within anenclosure 18 via aconnection 10. Theradar camera 80 may be wirelessly connected to thetraffic controller 16 if desired. Thetraffic controller 16 is connected viawire 82 to a computer/computing device 20 having memory for storing program instructions, programming, operating instructions and the like, as well as other typical electronic components of a computer/computing device. Thetraffic controller 16 may be wirelessly connected to the computer/computing device 20 if desired. Thetraffic controller 16 is also connected to the traffic light/signal 72 via wire or wirelessly. - The
radar camera 80 and/or the computer/computing device 20 are/is configured to monitor a field ofview 6 that includes a portion of the road and a stop bar area. The field ofview 6 may be adjusted as desired to cover a particular distance/area size. In accordance with the present invention, theradar camera 80 and/or the computer/computing device 20 further provides a rain intensity detection/measurement area/field ofview 9 for detectingrain intensity 81. The size of the area and distance covered by the detection/measurement area/field ofview 9 may be chosen as desired. - A
vehicle 4 is shown coming into the stop bar area being monitored by theradar camera 80 field ofview 6. The radar detects thevehicle 4 and sends a message to thetraffic controller 16. The traffic controller activates the green light on the traffic light/signal 72. The rain intensity detection/measurement area 9 is adjustable in distance from theradar camera 80. A typical value of measurement is ten feet (10′). Parameters or characteristics are derived from this radar measurement and used by the present invention, parameters/characteristics such as, but not limited to, raindrop count, raindrop size, size of raindrop reflection, and radar cross section of each raindrop. - During
heavy rain 81 the radar signal is attenuated and it becomes critical to ascertain when the intensity is at a level which will disrupt the detection of vehicles as they pull into the stop bar/detection area 6 or any other area where detection is desired. If the rain intensity detection is too sensitive the intersection loses efficiency. If the rain intensity detection is not quick enough then you risk vehicles being left stranded. - Rainfall intensity may be classified as described in Met Office (August 2007), “Fact Sheet No. 3: Water in the Atmosphere” and such may be used in the present invention. Other systems may be used. From the system, rain intensity may be classified as:
- Slight (Light) rain—when the precipitation rate is <2 mm (0.079 in) per hour.
- Moderate (Medium) rain—when the precipitation rate is between 2 mm (0.079 in) to 10 mm (0.39 in) per hour.
- Heavy rain—when the precipitation rate is between 10 mm (0.39 in) and 50 mm (2.0 in) per hour.
- Violent rain (Tropical Downpour)—when the precipitation rate is >50 mm (2.0 in) per hour.
- Microwave (radar) attenuation in dB can be characterized by rain intensity over frequency as shown in the graph of
FIG. 2 . This or similar information is preferably, but not necessarily, used in determining rain intensity per the present invention. The graph shows that violent rain/tropical downpour rainfall rates of greater than 2 inches/hour can cause significant attenuation at the frequency of interest, 24 GHz. Thus, the effectiveness of radar cameras is diminished. The map ofFIG. 3 shows that there are many areas in the United States where violent rain/tropical downpour situations occur. Thus, during these times, the operation of the traffic control system may be compromised. - A radar range calculation is:
-
- where: Radar Output Power is from the radar head product spec.
-
- Antenna Gain and Minimum Detectable Signal were adjusted to give correct range.
- Frequency is given.
- Radar Cross Section came from the link and table on the previous page.
- The table below summarizes radar degradation in worst case scenarios. The range utilized in the table below is based on the vehicle being a car. The range without rain attenuation is 600 feet:
-
Rain Level Range with Rain Range reduction 4 inches/hour 302 298 ~3 inches/hour 351 249 ~2.3 inches/hour 451 149 - Based on these calculations stop bar detection should remain functional through heavy rain conditions. There are situations where there is a need to be able to detect throughout the entire 600 feet range. In these situations, the radar detects the rain intensity and places a call to the traffic controller during the period that rain intensity is above the threshold.
- A signalized traffic control system may thus include rain intensity detection/determination per the principles of the present invention, in its traffic signal (light) operation. One method is presented in the
flowchart 100 ofFIG. 4 . The signalized traffic control system turns on with aStart 102. AfterStart 102, the Intersector (system) programming powers on, initializes, calibrates, error checks, sets a rain threshold, and initializesrain intensity programming 106. Thereafter, the radar camera is used to obtain measurement or data of the number of raindrops and raindrop size (via reflection) in order to calculate rain intensity (RI) by the formula RI=(# of raindrops)×(raindrop size)×(constant) 108. - The rain intensity is then compared to a rain intensity threshold (threshold) 110. If the rain intensity is greater than the threshold (True), then a rain intensity counter (counter) of a given interval (e.g. 5 minutes) is set 111. The calls on all outputs of the cabinet (traffic controller) are then placed and held. Thereafter the system continues 114 which waits for a rain event (or the continuation of the rain event) and takes
rain measurements 106. If the rain intensity is not greater than the threshold (False) the system determines if the rain intensity counter is zero (0) 116. If the rain intensity counter is not equal to zero (False), the rain intensity counter is decreased 117. Thereafter, the system continues 114, then waits for a rain event (or the continuation of the rain event) and takesrain measurements 106. If the counter is zero (True), normal operation of the traffic controller ensues, and calls are placed to the traffic controller as each car enters or is in thezone 118. Thereafter, the system continues 114, then waits for a rain event and takesmeasurements 106. - Another method of operating a signalized traffic control system with rain intensity detection is presented in the
flowchart 200 ofFIG. 5 . The signalized traffic control system turns on with aStart 202. AfterStart 202, the Intersector (system) programming powers on, initializes, calibrates, error checks, sets a rain threshold, and initializesrain intensity programming 206. Thereafter, the radar camera is used to obtain measurement or data of the number of raindrops and raindrop size (via reflection) in order to calculate rain intensity (RI) by the formula RI=(# of raindrops)×(raindrop size)×(constant) 208. Average rain intensity is then calculated using the currently calculated rain intensity and a given number of previously calculated rain intensity values (e.g. 19 previously calculated rain intensity values) 210. - The average rain intensity is then compared to a rain intensity threshold (threshold) 212. If the rain intensity is greater than the threshold (True), then a rain intensity counter (counter) of a given interval (e.g. 5 minutes) is set 213, and calls on all outputs on the cabinet (traffic controller) are placed and held. Thereafter the system continues 214 which waits for a rain event (or the continuation of the rain event) and takes
rain measurements 206. If the rain intensity is not greater than the threshold (False) the system determines if the rain intensity counter is greater than zero (0) 216. If the counter is not greater than zero (False), normal operation of the traffic control system ensues 218. Thereafter, the system continues 114, then waits for a rain event (or the continuation of the rain event) and takesrain measurements 106. If the counter is greater than zero (True), the rain timer and decremented 217. Thereafter, the system continues 114, then waits for a rain event (or the continuation of the rain event) and takesrain measurements 106. - Further to the method and the signalized traffic control system operation, the radar samples approximately twenty (20) times a second. From each sample a list of objects and radar properties may be created. In order to detect rain intensity, the radar is able to count the number of rain drops in the radar field of view in a short distance. The default range used is three (3) meters, or approximately ten (10) feet. In this range, the radar normally detects from 0 to 25 drops of rain depending on intensity.
- Radar also has a property where the reflected signal strength can be corrected to show equivalent Radar Cross Section (RCS). For a rain drop this is close to the size of the raindrop, experiments and calculations have shown the RCS varies from ˜0.010 inches to ˜0.40 inches in diameter. With these two parameters, a new variable called Rain Intensity Factor (RIF) is created. This variable is the product of Average Rain Drops (ARD) and Average of Radar Cross Section. The average is taken over a 0.5 second interval to smooth out the value and provide more uniform results. Other intervals may be used.
- Therefore, in one form, Rain Intensity=Average (Rain Drops)×(150-Average (Radar Cross Section in dB)). This new variable, Rain Intensity Factor, increases when either the number of rain drops increases or the size of the rain drops increases, which are directly correlated to increased rain intensity. From this, a customizable threshold can be set to specify the minimum rain intensity level to place a constant call to the traffic controller.
- The reaction to increasing rain is instantaneous, as soon as the Rain Intensity value crosses the Threshold value a “RAIN” alert is activated. In addition to holding the call while RAIN is above the threshold, the radar will hold the call for additional 5 minutes after the rain has dropped below the threshold to ensure everything is operating normally again. This time is programmable and could be set to any value.
- It should be appreciated that the components, structures, and/or features of the present invention may be altered as desired within the scope of the present disclosure.
Claims (19)
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110827558A (en) * | 2018-06-19 | 2020-02-21 | 芜湖岭上信息科技有限公司 | Traffic signal lamp recognition device based on vehicle speed, height of highlight area and image |
WO2020083716A1 (en) * | 2018-10-24 | 2020-04-30 | Valeo Schalter Und Sensoren Gmbh | Rain detection by means of an environment sensor for capturing the environment of a vehicle point by point, in particular by means of a lidar-based environment sensor |
CN111090133A (en) * | 2019-12-29 | 2020-05-01 | 亿水泰科(北京)信息技术有限公司 | Rainfall radar data quality control method |
DE102019111679A1 (en) * | 2019-05-06 | 2020-11-12 | S.M.S Smart Microwave Sensors Gmbh | Procedure for recording road users |
CN116092309A (en) * | 2023-01-05 | 2023-05-09 | 无锡车联天下信息技术有限公司 | Traffic light control method, device and system, electronic equipment and storage medium |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060055354A1 (en) * | 2004-09-14 | 2006-03-16 | Honda Motor Co., Ltd. | Automatic vehicle wiper system |
US20100309041A1 (en) * | 2006-11-17 | 2010-12-09 | Alebel Arage Hassen | Method and device for detecting precipitation by radar |
US20120038490A1 (en) * | 2007-06-29 | 2012-02-16 | Orion Energy Systems, Inc. | Outdoor lighting fixtures for controlling traffic lights |
US20130300583A1 (en) * | 2012-05-10 | 2013-11-14 | Leroy Samuel Wignot | System and Method for Configuring a Traffic Control Sensor System |
US20160370500A1 (en) * | 2015-06-18 | 2016-12-22 | J.F. Sabourin et associés Inc. | Method and server for providing alerts for rainfall return periods |
US20170001601A1 (en) * | 2015-07-03 | 2017-01-05 | Hyundai Motor Company | One body type rain sensor with reflection type sensor for detecting external object |
-
2017
- 2017-04-27 US US15/499,414 patent/US10551492B2/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060055354A1 (en) * | 2004-09-14 | 2006-03-16 | Honda Motor Co., Ltd. | Automatic vehicle wiper system |
US20100309041A1 (en) * | 2006-11-17 | 2010-12-09 | Alebel Arage Hassen | Method and device for detecting precipitation by radar |
US20120038490A1 (en) * | 2007-06-29 | 2012-02-16 | Orion Energy Systems, Inc. | Outdoor lighting fixtures for controlling traffic lights |
US20130300583A1 (en) * | 2012-05-10 | 2013-11-14 | Leroy Samuel Wignot | System and Method for Configuring a Traffic Control Sensor System |
US20160370500A1 (en) * | 2015-06-18 | 2016-12-22 | J.F. Sabourin et associés Inc. | Method and server for providing alerts for rainfall return periods |
US20170001601A1 (en) * | 2015-07-03 | 2017-01-05 | Hyundai Motor Company | One body type rain sensor with reflection type sensor for detecting external object |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110827558A (en) * | 2018-06-19 | 2020-02-21 | 芜湖岭上信息科技有限公司 | Traffic signal lamp recognition device based on vehicle speed, height of highlight area and image |
WO2020083716A1 (en) * | 2018-10-24 | 2020-04-30 | Valeo Schalter Und Sensoren Gmbh | Rain detection by means of an environment sensor for capturing the environment of a vehicle point by point, in particular by means of a lidar-based environment sensor |
DE102019111679A1 (en) * | 2019-05-06 | 2020-11-12 | S.M.S Smart Microwave Sensors Gmbh | Procedure for recording road users |
US11320518B2 (en) * | 2019-05-06 | 2022-05-03 | S.M.S. Smart Microwave Sensors Gmbh | Method for detecting road users |
CN111090133A (en) * | 2019-12-29 | 2020-05-01 | 亿水泰科(北京)信息技术有限公司 | Rainfall radar data quality control method |
CN116092309A (en) * | 2023-01-05 | 2023-05-09 | 无锡车联天下信息技术有限公司 | Traffic light control method, device and system, electronic equipment and storage medium |
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